Do alcohol expectancies and peer delinquency/substance use mediate the relationship between impulsivity and drinking behaviour in adolescence?

Aims: To investigate (1) whether aggressive and delinquent behaviour problems predict subsequent adolescent drinking behaviour; and (2) to what extent this association is mediated by alcohol expectancies and/or peer delinquency/substance use. Methods: 147 adolescents (approximately 15 years old) were interviewed with regard to their drinking behaviour. In addition, several self-rating questionnaires were given to gather information regarding the peers of these children. Results: As proposed by the Acquired Preparedness Model (APM), we found that behavioural problems were related to quantity and frequency of alcohol consumed, and that this relationship was mediated by alcohol expectancies. Regarding peer relations, we found positive correlations between drinking behaviour and peer delinquency/substance use, aggression/delinquency and alcohol expectancies. Furthermore, the association between behavioural problems and drinking decreased dramatically if peer delinquency/substance use was accounted for. A hierarchical regression analysis revealed that both alcohol expectancies and peer delinquency/substance use predicted alcohol consumption of adolescents at the 1-year follow-up above and beyond the effects of age, sex, family history of alcoholism and aggression/delinquency of respondents. Conclusions: Alcohol expectancies and peer delinquency/substance use are both crucial to the amount and frequency of adolescent alcohol use. They should be considered in designing prevention and intervention strategies in this age group.